Photographic materials for the silver dyestuff bleaching process



3,443,952. lcfi Patented May 1 1969 of such dyestuffs with the result that the layers become 3,443,952 opaque, especially when strongly acidic baths or baths PHOTO RAPH C MATERIALS FOR THE SILVER containing a high concentration of salt are used. sparingly DYESTUFF BLEACHING lfRofiEss soluble dyestuffs can also have a precipitating action on the Walter Anderau, Marly-le-Grand, Switzerland, assignor 5 gelatine; Very fine flocculation takes place and the i o iii aiviii i ii i iiis iiif iiiis fsi ei i ii giigggg precipitate is very difficult to bleach completely. This l s l d N 9 1964 makes it impossible to produce a pure white. Some dye- C mms pnonty app 5233 X an 0v stuffs or the decomposition products thereof also prevent Int CL 03 1 10 the bleaching of other layer dyestuffs. Finally, it is es U.S. CI. 96-99 4Claims 10 sential that the dyestuffs also possess a good fastness to light.

This invention is based on the observation that the ABSTRACT OF THE DISCLOSURE yellow dyestuffs having the general Formula 1 given beloW which, in accordance with the invention, are present in PhOtOgYaPhIC mateflal for the sllvef dyfistllfi bleachlng photographic layers, meet the above-mentioned requireprocess. This material contains on a support a layer @011- ments particularly well in respect of asborption maxima, taining silver halide and at least one yellow dyestuif Of transparency and behaviour during casting, drying and the formula processing of the layers. HOBS X X 80311 t t N=N NHO C-C CC ONH N:N

s Y Y S OQH 5 0311 in which X represents a hydrogen atom, an alkyl, lkoxy, Accordingly, the present invention provides photohydroxyalkoxy or alkoxyalkoxy group, Y represents a graphic materials for the silver dyestuffs bleaching process hydrogen atom or an alkyl group and Z represents a hywhich comprise on a support a layer containing at least drogen atom or a methyl group. These dyestuffs have an one dyestuff of the formula absorption maximum between 430 and 450 m are highly z Z HOsS X i l X SOaH transparent above 450 m and behave well during casting, in which X represents a hydrogen atom or an alkyl, alkoxy, drying and processing. hydroxyalkoxy or an alkoxyalkoxy group, Y represents a hydrogen atom or an alkyl group and Z represents a hydrogen atom or a hydrocarbon residue. A yellow dyestuff which is to be used in photographic Preference is given to dyestuffs of the formula material to be processed by the silver dyestuff bleaching in which X and Y have the meanings given above. The process for the production of images having a high degree substituent Y is preferably in ortho-position to the azo of light fastness and which are also otherwise permanent group, and the single substituents advantageously contain must possess a wide range of properties, Its absorption not more than four carbon atoms. maximum must be between 430 and 450 m and it must The dyestuffs of the Formula 1 may be prepared by be highly transparent in the range above 450 mu, or in reacting a dihalide of a thiophene-2,5-carboxylic acid other words, the absorption curve must show a sharp drop which may be further substituted in 3- and 4-positions by A yellow dyestuff having an absorption maximum below hydrocarbon residues, for example, phenyl groups, with 420 m may be designated a greenish yellow but it is of no an aminoazo dyestuff of the formula use in three-color material when color densities suitable (3) H033 X for mixed colors cannot be achieved with it. The dyestuff must also be nondiffusing. If the possession of this property depends on a paucity of groups imparting solubility in water, for example, carboxylic acid or sulfonic acid groups, Y the poor solubility of the dyestuff renders coloration of the gelatine difficult, and it is particularly difficult to S 3 achieve uniform coloration. Furthermore, opalescent moin which X and Y have the meanings given above, in a lecular association tends to occur in the layer in the case molar ratio of 1:2. It is advantageous to use thiophene-2,5-

3 4 dicarboxylic acid chloride for this reaction. The aminoazo Similar results were obtained when the dyestuff of the dyestuffs of the Formula 3 are obtainable by coupling Formula 4 was replaced by a symmetrical diazo dyestufi diazotized 2-aminonaphthalene-4,8-disulphonio acid with which also contained two residues of 2-aminonaphthaan aminobenzene containing the substituents X and Y lene-4,8-disulfonic acid, two residues of the formula indicated above. The following may be mentioned as examples of coupling components: aminobenzene, l-amino- 2- r 3-methylbenzene, 1-amino-2,5- or 2,6-dirnethylbenzene, l-amino-Z- or 3-methoxybenzene, 1-amino-2- ethoxybenzene, 1-amino-Z-B-hydroxyethoxybenzene, 1- amino-2-fl-methoxyethoxy-S-methylbenzene, l-amino-Z-B- hydroxyethoxy-S-methylbenzene and especially l-amino- 2-methoxy-5-methylbenzene. The dyestuffs of the Formulae l, 2 and 3 can be preand one residue of the formula pared by known methods. Coupling to form the aminoazo Higher! dyestuffs is carried out in an acid medium; amines that -0 0-0 C-O 0- are difficult to couple may be coupled in the form of their w-methane-sulphonic acids, the methane-sulphonic acid group being subsequently split 011?. The aminoazo dyestuffs Examples of the Tesldue are advantageously reacted with the thiophenedicarboxylic acid halide in the presence of an agent capable of binding acid. The photographic layers which, in accordance with the invention, contain at least one dyestutf of the Formula 1, can also be prepared and used for the production of colored photographic images in known manner.

In particular, the dyestuffs of the Formula 1 may be presar i ent in multilayer material which contains on a support a red-sensitized layer colored with a cyan dyestuff, a green- 1 CH3 sensitized layer colored with a magenta dyestufi and, fi- C nally, a blue-sensitized layer containing a dyestuir' of the Formula 1.

The following examples illustrate the invention. Unless (3333 otherwise stated, the parts and percentages are by weight.

-N=N NH- Example 1 Q 12 milligrams of the dyestuif of the formula 3 0 3 ill-CH3 H H HaC-(|) S0311 -N=N -NHO C-i 3 i-C ONHC N=N I H3O CH3 SOaH HOsS were dissolved in 2 cc. of distilled water at 70 C. The CH3 solution was cooled to C. and added to 3.5 cc. of 6% l aqueous gelatine havng a temperature of 40 C. 3.3 cc. N=N NH of a gelatine/ silver bromide emulsion having a temperature of 40 C. were then added, If desired or required, CH; 1 to 2 cc. of an aqueous solution of a spreading agent, for 4 example, saponine, and a hardening agent, for example, dimethylolurea could be added. The mixture so prepared was cast on a glass plate measuring 13 cm. x 18 cm. and dried. HaC 0 The layer was then exposed behind a stepped wedge l and the silver image developed in a 1-methylamino-4-hy- N=NNH droxybenzene sulphate hydroquinone developer and fixed.

The image dyestuff was then bleached out, in accordance with the amount of silver present, in a bath containing 30 to 100 parts by volume of 32% hydrochloric acid, 40 C to 120 parts of potassium bromide, 30 to 50 parts of thiourea and 0.001 to 0.01 parts of 2-amino-3-hydroxyphenazine per 1,000 parts by volume. Subsequently, excess silver was removed in a bath containing 100 parts of sodium chloride, 100 parts of copper sulphate crystals and Q 50 parts by volume of 37% hydrochloric acid per 1,000 E30 parts by volume. Fixation was then carried out in the usual manner. A yellow wedge was obtained which was the in- 8' O CH2CH2 OH verse image of the silver wedge and which was bleached 7O pure white at the areas where the silver was present at greatest density. A yellow image of the kind described Ha could also form a part of multicolor material; in this case the amount of gelatine used was adapted to suit 3 the thickness of layer required.

5 and:

The dyestuff of the Formula 4 could be prepared in the following manner:

60.6 parts of 2-aminonaphthalene-4,S-disulphonic acid in the form of the sodium salt were dissolved in 1,000 parts of water, the solution cooled to C. with ice and diazotized in the usual manner with 65 parts of 37% hydrochloric acid and 14 parts of sodium nitrite. 30.5 parts of 2-methoxy-5-methyl-1-aminobenzene were dissolved at 60 to 70 C. in 300 parts of water and 30 parts of 37% hydrochloric acid, the solution cooled to 5 C. with ice and added to the solution of the diazo compound. The batch was stirred for 24 hours at 8 to C., during which period coupling to form the aminomonoazo dyestuff was completed. The time required for coupling could be shortened by buffering the mineral acid with sodium acetate. The acidic suspension of the monoazo dyestuif was heated to 65 C. and then filtered at 30 C.

The precipitated monoazo dyestulf was suspended in 1,000 parts of water, dissolved and neutralized with sodium carbonate and the solution then made slightly alkaline with sodium carbonate. The solution was heated to 25 :2 C. and 30 parts of sodium acetate crystals were added followed by 22 to 24 parts of thiophene-2,5-dicarboxylic acid dichloride dissolved in 100 parts of acetone. The reaction took 15 to hours to complete at 25 C. If necessary, sodium hydroxide could be added to maintain the pH value at 9 to 9.4. After the condensation the batch was heated to 65 C. and 12 parts of sodium carbonate added. After cooling the reaction mixture to 40 C. it was filtered and the by-products washed out of the condensate with ethanol and acetone. The dyestuff was then dried. The dyestutf could be manufactured almost completely free from salt, the procedure being to stir the moist paste into distilled water, heating the suspension to 50 C., improving the form of the suspension by the addition of a small amount of potassium acetate solution to make it readily filterable and then filtering the suspension, washing the potassium acetate out of the press cake with alcohol and drying.

Dyestuffs containing the residues 1 to 9 indicated above could also be prepared by this procedure, the constitution of the starting materials being indicated by the formulae.

Example 2 The following layers were applied in the sequence indicated to a white opaque acetate film provided with an adhesive layer:

(1) A red-sensitized silver bromide emulsion in gelatine containing the cyan dyestuif of the formula (4) A yellow filter layer containing the dyestutf of the formula (5) A blue-sensitized silver bromide emulsion in gelatine containing the yellow dyestutf of the Formula 4.

The gelatine layers could also contain additives for example wetting agents, hardening agents and stabilizers for the silver halide. The material was manufactured in a manner such that the single layers contained, per square meter of film, 0.5 gram of dyestufl and silver bromide in an amount corresponding to 1 to 1.2 grams of silver.

The film so prepared was exposed beneath a colored diapositive to red, green and blue light. The reproduction was then developed according to the following procedure: 1) Developing for 6 minues in a bath containing 50 grams of anhydrous sodium sulphate, 0.2 gram of 1- phenyl-3-pyrazolidone, 6 grams of hydroquinone, 35

grams of anhydrous sodium carbonate, 4 grams of potassium bromide and 0.3 gram of benztriazole per liter of water;

(2) Washing with water for 5 minues;

(3) Fixing for 6 minutes in a solution of 200 grams of Similar good results could be obtained by incorporatsodium thiosulphate crystals and 20 grams of potassium metabisulfite in 1 liter of water;

(4) Washing with water for 5 minutes;

(5) Bleaching of the dyestuffs for 3 to 12 minutes with a solution containing, per liter of water, 50 to 80 grams of potassium bromide, 40 to 80 grams of thiourea, 35 to 80 grams of 30% sulphuric acid and, if desired, 0.01 gram of 2-amino-3-hydroxyphenazine;

(6) Washing with water for 10 minutes;

(7) Bleaching of the residual silver for 5 minutes with a solution of grams of copper sulfate crystals, 80 grams of potassium bromide and 15 ml. of 30% hydrochloric acid in one liter of water;

(8) Washing with water for 5 minutes;

(9) Fixing for 5 minutes in the manner described under (10) Washing with water for 5 minutes.

A positive image to be viewed in incident light was obtained which was fast to light and which is also otherwise permanent.

OH HOaS Similar good results could be obtained by incorporating any one of the yellow dyestuffs containing the residues l to 9 in the blue-sensitized layer instead of the dyestuif of the Formula 4.

l SOaH HO 7 8 Example 3 hydrogen atom or an alkyl group and Z represents a hydrogen atom or a methyl group.

The Procedure was the Same as that descnbed 2. Photographic materials as claimed in claim 1 in amples 1 2 but the Yellow dyestuff f the Formula 4 which one layer contains silver halide and a dyestutf of was replaced by the dyestuif of the formula 5 the formula H038 X X sosH I H?( ?H l N=N NH-O C( 0-0 OHN-- N=N s Y Y soar 110 s H3O OH; 11038 HaC-O I 5 0-4111: son: N=N NH-O o-ii i l-C O-HN N=N Ha CH3 H033 S OaH This dyestutf was prepared in a manner analogous to that described in Example 1 except that the to 24 parts 25 in which X represents a hydrogen atom or an alkyl, alkof thiophene-2,5-dicarboxylic acid dichloride were reoxy, hydroxyalkoxy or alkoxyalkoxy group and Y repreplaced by 25 to 28 parts of 3,4-dimethyl-thiophene-2,5- sents a hydrogen atom or an allryl group.

dicarboxylic acid dichloride. 3. Photographic materials as claimed in claim 1 in What is claimed is: which one layer contains silver halide, and a dyestutf of 1. Photographic materials for the silver dyestutf bleach- 30 the formula given in which the substituent Y is in orthoing process which comprises on a support a layer conposition to the azo group and each substitutent contains taining silver halide and at least one dyestuff of the fornot more than four carbon atoms. mula 4. Photographic materials as claimed in claim 1 in Ross X X SOaH in which X represent a hydrogen atom or an alkyl, alkoxy, which one layer contains silver halide and the dyestulf of hydroxyalkoxy or alkoxyalkoxy group, Y represents a the formula H3 C 0 Ha References Cited UNITED STATES PATENTS 2,899,305 8/ 1959 Bossard et al. 9699 3,178,291 4/1965 Mory et a1 96--99 J. TRAV IS BROWN, Primary Examiner.

U.S. Cl. X.R.

P0405 UNITED STATES PATENT OFFICE 56 CERTIFICATE OF CORRECTION Patent No. 3,1M3,952 Dated May 13, 1969 Inventor(5) WALTER ANDERAU It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 8, claim in the formula, that portion reading H C H should read SIGNED AN'D SEALED (SEAL) Attest:

Edward M. Fletcher, Ir.

Attesting Officer Commissioner of Patents WILLIAM E- SCIHUYLER, JR. 

